There’s a lot of interest in this topic these days. On Aug. 1, the Department of Health and Human Services approved a recommendation from the Institute of Medicine, an arm of the National Academy of Sciences, saying all insurers should cover contraceptives for women free, as one of several preventive services under the new health care law. That recommendation is to become standard practice–but not until 2013. It will not affect uninsured women.

We dug around, and identified some of the top-selling oral contraceptives. Then we looked at the out-of-pocket cost for a one-month supply. The results—which are still admittedly anecdotal—surprised us. The price of your pill might just depend on the block on which you choose to buy it.

Here are some of the takeaways: Newer drugs like Yaz and its generics are expensive. But independent pharmacies tended to charge less than the chain pharmacies in the same neighborhood for brand name contraceptives—a $5 or $10 savings. The price of Ortho Tri-Cyclen Lo also varied, as did the cost of more established Ortho generics.

Places like Rite Aid often have pharmacy cards, which can offer up to a 20 percent discount on brand name drugs. That could even things out, especially over the long term. The Costco in New Rochelle, N.Y., where a month supply of Yaz went for $80.78, was the clear steal in our little survey. Of course, you have to be a Costco member. Membership is $50 annually,which would add $4.17 monthly to that price tag.

Now we need your help. We want to create a resource to help make the true cost of common prescriptions like birth control more accessible, showing the variations from block to block, town to town, and coast to coast.

We have tried to make the Price of Birth Control map simple. This is what we need from you: Go to your pharmacy. Ask about cost. Then add it to the map. With your help, we’ll build out a resource for women across the country.